Upload a video, pick a speed from 0.25x to 4x, preview it instantly, then export the sped-up or slowed-down clip. Nothing is uploaded.
Processed and encoded on your device. Nothing is uploaded to a server.
Selecting a speed chip sets the video element's playback rate directly, so you can preview any speed instantly before exporting. Exporting plays the clip through at that same rate while every frame is drawn to a canvas and the canvas stream, along with the video's audio track when your browser supports capturing it, is recorded straight to a WebM file in your browser.
The export keeps your source video's native width and height, only capped down if the longest edge is larger than 1280px.
Because export plays the file through at the chosen rate, the audio track is captured already sped up or slowed down along with the picture.
Yes. Both video and audio play back at the chosen speed together, the same way changing playback speed works in a normal video player.
Yes, at speeds other than 1x the audio pitch will sound higher when sped up or lower when slowed down. This tool leaves the browser's default playback behavior alone rather than trying to preserve pitch, so this is expected and not a bug.
No. The file is loaded directly into your browser and the sped-up or slowed-down clip is recorded locally with the MediaRecorder API. Nothing is sent to a server.
Clips are exported as WebM, which plays in all modern browsers and can be re-encoded to MP4 with most video editors if you need that format.
Export works by actually playing the clip through at the chosen speed and recording it as it plays, so a 0.25x export of a long clip takes four times as long as the export itself would at normal speed.
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